The measurement of oxygen delivery to the body and the corresponding oxygen consumption by its organs and tissues is vitally important to medical practitioners in the diagnosis and treatment of various medical conditions. Oxygen delivery is useful, for example, during certain medical procedures, where artificially providing additional oxygen to the patient's blood stream may become necessary. For example, during an intubation procedure, the patient will stop breathing while the procedure is performed. The patient is typically provided with oxygen before the intubation procedure. Because the patient stops breathing during an intubation procedure, the patient's blood oxygen saturation level will fall. In that situation, the medical practitioner must ensure that the patient has sufficient reserves of oxygen in their system before intubation so that during the intubation procedure suffocation is avoided. At the same time, providing oxygen at a high pressure to a patient can cause damage to the alveoli of an adult patient. On the other hand, even normal oxygen levels can or cause blindness in neonatal patients.
The current standard of care is to measure oxygen delivery through the use of a pulse oximeter. Pulse oximeters measure oxygen saturation (SpO2). SpO2 represents the percent of available hemoglobin that can chemically bind with oxygen molecules.
Another indicator of oxygen delivery is the partial pressure of oxygen (PaO2), However, there are currently no reliable ways to measure PaO2 noninvasively. Invasive PaO2 measurements require expensive sensors and are known to carry serious side effects that can harm the health of a patient.